Do it yourself, remove the front door panel on your Cadillac CTS produced in the year 2005. You will need a flathead screwdriver and a Phillips screwdriver. You may want to make this removal if you need to get access the mechanism on the door, to repair the window regulator, change the speaker on the door, etc. The removal process won’t take you more than 15 minutes.
The first thing you should do is to pry out the trim panel around the door handle. Insert a flat blade screwdriver (you can wrap a rag around it to protect the plastic parts) behind it and pry out carefully until the plastic panel pops out. After you detach it, you will have to unplug the wiring harness behind the panel, that powers up the door lock switch (see picture below for details).
Then, using the same screwdriver, pry out the small cover beneath the interior door handle. It will uncover the two Phillips screws shown in the image below, that you will have to remove.
Now, go to the door lock and pry out a small plastic tab that secures it, as shown in the next picture. Then simply pull up the door lock from its rod.
At this point you can pull out the front door panel. It has a series of retaining clips that attach it do the door frame. Pull it out firmly, but carefully not to bend the plastic, and remove it from the door. These are the steps you need to know and follow if you need to remove the door panel on your Cadillac CTS, made in 2005.